Maria Shriver spent the weekend doing what most moms do; taking her kids all over!

We spotted Shriver in both Santa Monica and Beverly Hills -- in Santa Monica, she headed with daughter Katherine, 21, and son Christopher, 13, to a Special Olympics event on Sunday. Katherine Tweeted: "At pier del aol in Santa Monica with my mama @mariashriver for @SpecialOlympics !! Yummy and fun day!!"